Fujitsu MBC2036RC, MBC2073RC, MBA3300RC, MBA3147RC Information units, Command information unit

1.6 Transport layer

If necessary, fill bytes are placed after the INFORMATION UNIT field so that the CRC field is aligned on a four-byte boundary. The number of the fill bytes is specified by the NUMBER OF FILL BYTES field. If the transferred bytes in the last DATA frame are not aligned on a four byte boundary, this field is set to the number of the extra bytes (4 - the remainder of (the number of transferred bytes/4) bytes).

The CRC field contains a CRC value that is computed over the entire SSP frame prior to the CRC field including the fill bytes (i.e., all data dwords between the SOF and EOF).

Drives ignore the Reserved fields.

1.6.2 Information units

1.6.2.1COMMAND information unit

Table 1.34 defines the command IU. The COMMAND frame is sent by an SSP INIT port to request that a command be processed by the device server in a logical unit.

Table 1.34 COMMAND information unit

Bit	7	6	5	4		3	2	1	0
Byte
0	(MSB)		LOGICAL UNIT NUMBER
7									(LSB)
8					Reserved
	ENABLE
9	FIRST		Reserved				TASK ATTRIBUTE
	BURST
10					Reserved
11	ADDITIONAL CDB LENGTH						Reserved
		(n dwords)
12	(MSB)				CDB
27									(LSB)
28			ADDITIONAL CDB BYTES
27+ n x 4

The LOGICAL UNIT NUMBER field contains the address of the logical unit.

An ENABLE FIRST BURST bit set to "1" specifies that the first burst data item is transferred as defined by the FIRST BURST SIZE field in the Disconnect- Reconnect mode page. However, drives do not support this bit. Therefore, a drive ignores the FIRST BURST SIZE field of the Disconnect-Reconnect mode page.

Table 1.35 contains the definitions of the TASK ATTRIBUTE field. However, drives do not support ACA in Table 1.35. Moreover, when a reserved TASK

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